In recent years, liquid crystal display devices, for example, are being widely used in liquid crystal televisions, monitors, mobile telephones, and the like, as flat panel displays having advantages such as being thinner and lighter compared to previously existing cathode-ray tube displays. Among such liquid crystal display devices, one is known in which the liquid crystal panel, which functions as the display panel, includes an active matrix substrate that has a plurality of data wiring lines (source wiring lines) and a plurality of scan wiring lines (gate wiring lines) wired in a matrix form, and a plurality of pixels, each of which is provided with a switching element such as a thin film transistor (TFT) and a pixel electrode connected to the switching element, arranged in a matrix in the vicinity of the respective intersections of the data wiring lines and the scan wiring lines.
For an active matrix substrate such as the one described above, one in which a plurality of non-volatile memories that can store data are provided aside from the pixels is proposed. In such an active matrix substrate, switching elements such as thin film transistors for selection are provided in order to select each of the plurality of non-volatile memories. In other words, such an active matrix substrate uses a semiconductor device provided with the non-volatile memories having a plurality of thin film transistors for selection.
Among conventional semiconductor devices, it has been proposed that thin film transistors for pixels and thin film transistors for selection be formed on a substrate in the same process, and the thin film transistors for the pixels and non-volatile memories be also provided together on the same substrate, as disclosed in Patent Document 1 to be mentioned below, for example.